In the optical absorption technique for blood glucose quantification, the near infrared (NIR) spectral region has been demonstrated to be a highly suitable range. This is because within this range, the water absorption spectrum is relatively minimised, and the peak glucose levels can be readily identified.
Within this range, useful peak glucose absorption wavelengths have been identified at, for example 1200 nm, 1290 nm, 1570 nm, 1650 nm, 2270 nm, 2310 nm, etc. At these optimal values, glucose monitoring may be performed with highly accurate results.
It is desirous for optical absorption techniques for blood glucose monitoring, to obtain and sustain these wavelengths in turn, so that they may be used for blood glucose monitoring purposes of a patient.
Presently, the Acousto-Optic Tuneable Filter (AOTF) is used to generate the NIR spectral region for this purpose. The AOTF setup is not only expensive and bulky, the use of acousto optics for selection of wavelengths is highly dependent on the temperature. This is because a change in temperature would bring about a change in the velocity of sound, which in turn influences the wavelengths generated. It can be appreciated that the stability of each tuned wavelength is also a concern.
There is therefore a need to provide an economical means for generating and obtaining optimal wavelength values for reliable and accurate glucose monitoring